The Seasonal Variation of Mesospheric Temperature Estimated from VHF Meteor Radar at King Sejong Station (62.2, 58.8), Antarctica

Abstract

A VHF meteor radar and SATI instruments have been operated at King Sejong Station (62.2？

, 58.8？

), Antarctica, to study the mesospheric characteristics in southern high latitude region since March 2007 and February 2002, respectively. Using data from two instruments, we estimated the mesospheric temperatures according to the Hocking (1999)？

method, which requires the slope of logarithmic inverse decay times vs. height and the temperature gradient at meteor peak altitude, during March 2007 through July 2009 and compared the results with the SATI temperatures. The temperatures derived from observed decay times seem to be consistent with the rotational temperatures of SATI OH(6-2) and O2(0-1) emission during March through October. The annual variation of estimated temperatures, which clearly shows a minimum during southern summer, is a good agreement with observations at other stations. The mean estimated temperature during summer which is much colder than that of CIRA86 model, as much as by 30 K, is comparable with the results of L？

bken et al. (1999) which reported the mean mesopause temperature of 120 to 140 K from in-situ measurements using falling spheres performed at Rothera Station (68？

, 68？

). In addition, from the results of meridional wind analysis, it was found that the equator-ward meridional winds are dominant flows during southern summer. In this study, we discuss the seasonal variations of mesospheric temperatures estimated from meteor decay times and the relation between the estimated temperatures and meridional wind measured from same instrument.